The present invention relates to an image transfer product such as a printing blanket or printing sleeve, and more particularly, to an improved image transfer product including a thin printing surface layer in combination with a smooth image reinforcement layer.
One of the most common commercial printing processes is offset lithography. In this printing process, ink is offset from a printing plate to a rubber-surfaced printing blanket mounted on a blanket cylinder before being transferred to a substrate, such as paper. Typically, the printing blanket includes at least one base ply which comprises the blanket carcass and an outer printing surface layer which is typically formed from a polymeric rubber material. The printing surface layer is adapted to carry and transfer liquid printing ink.
Most printing surface layers currently in use typically comprise natural or synthetic rubber materials which require the use of a solvent to dissolve the rubber material so that it may be coated, in numerous thin passes, onto the base ply. The solvent must then be evaporated prior to curing. Alternatively, the natural or synthetic rubber materials may be calendared onto the base ply in a single pass, but at great expense due to the need to adequately control gauge. In both methods, the rubber materials must be cured under pressure, which is a time consuming process.
Accordingly, there is still a need in the art for an improved method of making an image transfer product such as a printing blanket or sleeve including a printing surface having the desired gauge and texture for receiving and transferring ink without the drawbacks of prior methods.